April 2, 1998

A weekly feature provided by scientists at the Hawaiian Volcano
Observatory.

Where will the next Hawaiian volcano be?

As we all know, there are no facts about the future. We cannot know for sure what
will happen tomorrow, much less next year or 1,000 years from now. How, then, can
we be so bold as to guess where the next volcano will form in Hawai`i, perhaps
100,000 years or more down the road?

If volcanoes were scattered randomly throughout the Hawaiian Islands, no one
could say where the next volcano might start erupting. It would be like trying to guess
the winning number in the lottery. Once in a while someone gets lucky, but most of us
lose.

But volcanoes in Hawai`i are not lottery numbers. They occur in a remarkably
systematic arrangement, and we have learned enough about this pattern to make a
pretty good guess as to where the next volcano will form.
For starters, the volcanoes get younger toward the southeast end of the island
chain. The first Polynesians to settle in the islands recognized this, 19th-century
naturalists confirmed it, and late 20th-century earth scientists found a reason for this
pattern.

The thin Pacific plate of the earth's crust moves northwestward about 13 cm (5
inches) a year. The plate rides over a hot spot or plume that causes rock below the
crust to melt and slowly float toward the surface. Some of the melted rock, called
magma, erupts to form a volcano on the Pacific plate. The volcano is carried away
from the hot spot as the plate continues to move northwestward. The volcano
eventually loses contact with the hot spot and dies. Another volcano takes its place
over the hot spot, and the beat goes on--always birth to the southeast and death to the
northwest.

Not only do the volcanoes get younger toward the southeast, but they are spaced
about the same distance apart and occur on one of two gently curving lines. If you
don't believe it, get out a map. Starting from O`ahu, you will see that one line of
volcanoes includes Wai`anae, Ko`olau, West Moloka`i, Lana`i, Kaho`olawe, the
submerged volcano of Mahukona, Hualalai, Mauna Loa, and Lo`ihi. The summits of
these volcanoes are spaced about 40-60 km (25-40 miles) apart.

Another parallel line a little farther east includes East Moloka`i, West Maui, East
Maui (Haleakala), Kohala, Mauna Kea, and Kilauea. These volcanoes are also about
40-60 km (25-40 miles) apart, except for a gap between Haleakala and Kohala in
which another small volcano may have formed but is now obscured.
These two lines were first recognized in the 19th century by the famed naturalist
James Dana, who named them the Loa (from Mauna Loa) and Kea (from Mauna Kea)
lines, respectively.

Lo`ihi is at the southeastern end of the Loa line. It is in the process of taking over
from Mauna Loa, which some evidence suggests may already be in a state of slow
decline. Kilauea is at the end of the Kea line and is obviously still full of vigor. But
eventually it will be replaced by the next Hawaiian volcano, which, judging from the
spacing up the chain, will be centered some 40-60 km (25-40 miles) southeast of
Kilauea. It will become Lo`ihi's rival, much as Kilauea is today the rival of Mauna Loa.

Former HVO directors Jim Moore and Dave Clague feel so confident about the
location of the next volcano that they have already named it: Keikikea, "child of Kea."
The birth of Keikikea is probably still in the future a few tens of thousands of years or
more, though, so don't hold your breath.

Eruption and Earthquake Update

There were no changes in the activity of the east rift zone eruption of Kilauea
Volcano from the vent at Pu`u `O`o. Lava continued to flow through a network of tubes
down to the seacoast where it entered the ocean at two locations - Waha`ula and
Kamokuna. The public is reminded that the ocean entry areas are extremely
hazardous, with explosions accompanying frequent collapses of the lava delta. The
steam cloud is highly acidic and laced with glass particles.

There were no earthquakes reported felt during the past week.

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Contact:
hvowebmaster@usgs.govUpdated:
7 April 1998